Skid-mounted structure integrated seawater pretreatment system applied to oil platform

Abstract

The utility model relates to a skid-mounted structure integrated seawater pretreatment system applied to an oil platform, which is characterized in that a self-cleaning filter, a seawater heat exchanger and an ultrafiltration system adopt a skid-mounted structure to form four skid-mounted units; the cyclone desander skid-mounted unit, the self-cleaning filter skid-mounted unit, the seawater heat exchanger skid-mounted unit and the ultrafiltration system skid-mounted unit are sequentially connected to form an integrated structure, and seawater sequentially flows through the four skid-mounted units. The system is used for removing and reducing floating objects, planktons, bacteria, microorganisms, suspended solids and colloidal particles in seawater, heating the seawater to maintain the temperature of the seawater at the designed water temperature, and treating the seawater into inflow water meeting the subsequent reverse osmosis seawater desalination. The system adopts an integrated multifunctional process, is not influenced by severe environments such as low-temperature sea areas and high-turbidity seawater conditions, is suitable for various sea areas, and has the characteristics of wide adaptability, stable operation, high reliability and good treatment effect. The skid-mounted structural design has the characteristics of few connecting pipelines, compact structure and small occupied area.

Description

Technical Field

[0001] The utility model relates to the technical field of reverse osmosis seawater desalination, in particular to a skid-mounted structure integrated seawater pretreatment system. Background Art

[0002] The reverse osmosis desalination technology basically adopts a combination of front-end pretreatment, main desalination, and post-treatment refining processes. The main purpose of the front-end pretreatment process is to remove suspended matter, microorganisms, and colloidal particles, etc., and generally focuses on coagulation, sedimentation, filtration, and ultrafiltration. The core unit of the main desalination process is the reverse osmosis membrane assembly. Seawater is separated and purified through the reverse osmosis membrane with pressure difference as the driving force, and water molecules pass through the membrane to become fresh water. The main purpose of the post-treatment refining process is to increase the alkalinity, hardness, deoxygenation, and pH to the standard value for use. Generally, it focuses on mineralization, pH adjustment, thermal deoxygenation, and disinfection.

[0003] If the reverse osmosis desalination pretreatment technology is not used properly, it will cause the reverse osmosis membrane to be fouled and scaled, leading to increased system operation, maintenance, energy consumption, core component replacement and water production costs of the main desalination and post-treatment refining processes. Therefore, a reasonable pretreatment process is one of the decisive factors for the successful operation of the entire reverse osmosis desalination technology.

[0004] At present, the traditional seawater pretreatment process system has the following characteristics: first, it has a single function and poor adaptability to harsh environmental conditions such as low-temperature seawater and high-turbidity seawater conditions in winter; second, it has a decentralized structure, with each unit arranged in a dispersed manner, occupying a large area and having many connecting pipelines. With the construction of my country as a maritime power, seawater desalination technology needs to be promoted and applied to low-temperature polar waters, high-turbidity coastal waters, and limited operating platforms or ships. By optimizing the integrated seawater pretreatment process unit and adopting integrated skid-mounted structure design technology, the above situation can be effectively solved and new development needs can be adapted. Therefore, it is necessary to design a skid-mounted integrated seawater pretreatment system for oil platforms, which is used for the treatment process before seawater enters the reverse osmosis desalination process, removes substances harmful to subsequent processes from seawater or reduces their content, and meets the water quality requirements of the subsequent seawater desalination equipment. Summary of the invention

[0005] The purpose of the utility model is to provide a skid-mounted integrated seawater pretreatment system for oil platforms. By rationally optimizing the integrated seawater pretreatment process unit and adopting a skid-mounted structural design, it can adapt to low-temperature polar waters, high-turbidity coastal waters, and limited operating platforms or narrow ship space. First, it greatly reduces the footprint and pipeline connections; second, it effectively solves the risks of reverse osmosis membrane fouling and scaling, reduces the operation, maintenance, energy consumption, core component replacement and water production costs of the reverse osmosis seawater desalination system, and improves overall operational stability and reliability. It is not affected by harsh environments such as low-temperature seas and high-turbidity seawater conditions, and is suitable for various sea areas with wide adaptability. The skid-mounted structural design has the characteristics of fewer connecting pipelines, compact structure, and small footprint.

[0006] To achieve the above-mentioned purpose, the technical solution of the utility model is: a skid-mounted structure integrated seawater pretreatment system applied to an oil platform, comprising: a cyclone desander, a self-cleaning filter, a seawater heat exchanger, and an ultrafiltration system; the cyclone desander, the self-cleaning filter, the seawater heat exchanger, and the ultrafiltration system adopt a skid-mounted structure to form four skid-mounted units, and the cyclone desander skid-mounted unit, the self-cleaning filter skid-mounted unit, the seawater heat exchanger skid-mounted unit, and the ultrafiltration system skid-mounted unit are sequentially connected to form an integrated structure, which is used for seawater to flow through the four skid-mounted units in sequence for treatment.

[0007] Furthermore, the cyclone desander skid-mounted unit integrates the water pump, cyclone, pipelines and valves, instruments, electric control box and frame in an integrated manner. The water pump, cyclone, pipelines and valves, instruments and electric control box are all installed in a common frame.

[0008] Furthermore, the self-cleaning filter skid-mounted unit integrates the motor, pipelines and valves, filter screen, electric control box and frame. The motor, pipelines and valves, filter screen and electric control box are all installed in a common frame.

[0009] Furthermore, the seawater heat exchanger skid-mounted unit integrates the heat exchanger, pipelines and valves, instruments and frames, and the heat exchanger, pipelines and valves, and instruments are all installed in a common frame.

[0010] Furthermore, the ultrafiltration system skid-mounted unit integrates water pumps, ultrafiltration membranes, ultrafiltration membrane tanks, pipelines and valves, instruments, electrical control boxes and frames. The water pumps, ultrafiltration membranes, ultrafiltration membrane tanks, pipelines and valves, instruments, and electrical control boxes are all installed in a common frame.

[0011] Furthermore, the UF system skid-mounted unit adopts an immersed UF system, using membrane separation technology to replace traditional sedimentation tanks and conventional sand filtration units.

[0012] The beneficial effects of the utility model are:

[0013] 1. By rationally optimizing the treatment process of the seawater pretreatment system, the enhanced pretreatment process of the cyclone desander, self-cleaning filter, seawater heat exchanger and ultrafiltration system is integrated to improve the overall environmental adaptability of the system, meet the working conditions of low temperature and high turbidity seawater, and ensure the stability of the water quality of the pretreatment system.

[0014] 2. Skid-mounted structural design, modular functions of each process unit, compact structure, small footprint, high space utilization, easy installation, simple piping and convenient operation and management. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram of a skid-mounted structure integrated seawater pretreatment system of the utility model;

[0016] Figure 2 It is a schematic diagram of the skid-mounted structure of the seawater pretreatment system of the utility model;

[0017] Among them: (a) is a cyclone desander, (b) is a self-cleaning filter, (c) is a seawater heat exchanger, (d) is a part of the ultrafiltration system, and (e) is the entire ultrafiltration system. DETAILED DESCRIPTION

[0018] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0019] like Figure 1 As shown, the utility model provides a skid-mounted integrated seawater pretreatment system for oil platforms, including: a cyclone desander 1, a self-cleaning filter 2, a seawater heat exchanger 3, and an ultrafiltration system 4; the cyclone desander 1, the self-cleaning filter 2, the seawater heat exchanger 3, and the ultrafiltration system are skid-mounted to form four skid-mounted units, and the seawater flows through the four skid-mounted units in sequence. The main function of the system is to remove and reduce floating objects, plankton, bacteria and microorganisms, suspended matter, and colloidal particles in seawater, and to heat the seawater to maintain the designed water temperature, and to treat the seawater into water that meets the requirements of subsequent reverse osmosis desalination.

[0020] The skid-mounted structure has modular functions for each process unit, compact structure, small footprint, high space utilization, easy installation, simple piping and convenient operation and management. The integrated seawater pretreatment system has a multifunctional process with perfect technology and complete functions, including hydraulic cyclone separation, screen microfiltration, waste heat utilization to heat seawater and ultrafiltration membrane separation process, which can process seawater into water that meets the requirements of subsequent reverse osmosis desalination.

[0021] like Figure 2As shown in (a), the skid-mounted unit of the cyclone desander integrates the water pump, cyclone, pipelines and valves, instruments, electric control box and frame, etc. All parts are installed in a common frame. Based on the principle of sedimentation and density difference, the centrifugal force of seawater in the cyclone is used to separate the solid particles in the seawater and discharge them through the sand discharge port.

[0022] like Figure 2 As shown in (b), the self-cleaning filter skid unit integrates the motor, pipeline and valve, filter, electric control box and frame, etc. All parts are installed in a common frame. According to the principle of screening, the filter directly intercepts suspended matter and small particles above 200μm in seawater, and automatically cleans and discharges the filter at the same time. During the cleaning and discharge, the system continuously produces clean water.

[0023] like Figure 2 As shown in (c), the seawater heat exchanger skid-mounted unit integrates the heat exchanger, pipelines and valves, instruments and frames, etc. All parts are installed in a common frame. The seawater temperature has a great influence on the water output of the subsequent ultrafiltration membrane system and reverse osmosis system. For every 1°C decrease in temperature, the output decreases by about 1-3%. In winter, the output drops to about 50% under low temperature conditions. The seawater heat exchanger uses the high-temperature deoxygenated water of the thermal deaerator of the post-processing refining unit to heat the low-temperature seawater of the self-cleaning filter skid. After the low-temperature seawater flows through the seawater heat exchanger skid and is heated, the outlet water temperature stabilizes at the design value and then passes through the subsequent ultrafiltration system and reverse osmosis system. This greatly reduces the working pressure of the ultrafiltration system and reverse osmosis system and reduces the system energy consumption. The seawater heat exchanger skid makes secondary use of the waste heat, increases the seawater inlet temperature in winter, and saves energy and protects the environment.

[0024] like Figure 2 As shown in (d) and (e), the skid-mounted unit of the ultrafiltration system integrates water pumps, ultrafiltration membranes, ultrafiltration membrane pools, pipelines and valves, instruments, electric control boxes and frames, etc. All components are installed in a common frame. An immersed ultrafiltration system is adopted, and membrane separation technology is used to replace traditional sedimentation tanks and conventional sand filtration units. Therefore, it has high-efficiency solid-liquid separation performance. At the same time, it utilizes the characteristics of the membrane to effectively remove impurities such as silt and colloids in the raw water. The effluent water quality is good and stable, and the effluent bacteria, suspended solids and turbidity are close to zero. It can also intercept biological pollutants such as fecal coliform bacteria, and the effluent can directly enter the reverse osmosis system after treatment. In order to adapt to the problem of seawater in high turbidity sea areas, an ultrafiltration pretreatment system is integrated to reduce the fouling and scaling of reverse osmosis, greatly extending the cleaning cycle of reverse osmosis and the service life of the membrane.

[0025] Example 1: Integrated seawater pretreatment system

[0026] Reference Figure 1As shown, the seawater pretreatment system includes a cyclone desander skid 1, a self-cleaning filter skid 2, and an ultrafiltration system skid 4; the seawater first passes through the cyclone desander skid 1, and large suspended impurities are discharged from the system after being hydrocycloned; the seawater is then filtered through the self-cleaning filter skid 2, and smaller suspended matter and particles in the seawater are intercepted by the filter screen, and the device automatically cleans the filter screen and discharges sewage; the low-temperature seawater flows through the seawater heat exchanger skid 3 and is heated, and the outlet water temperature is stabilized at a design value of about 25°C, and then passes through the subsequent ultrafiltration system and reverse osmosis system, which greatly reduces the working pressure of the ultrafiltration system and the reverse osmosis system and reduces the system energy consumption. It should be noted that high turbidity seawater contains large particles of sediment, suspended matter, small particle size pollutants, colloids and other substances; it should be noted that the traditional pretreatment process of coagulation sedimentation and pressure filtration process has a large equipment volume and the outlet water quality is greatly affected by the change of seawater temperature; it should be noted that under low temperature conditions in winter, the water output of the subsequent ultrafiltration membrane system and reverse osmosis system decreases by about 50%.

[0027] Example 2: Skid-mounted structure design

[0028] Reference Figure 2 As shown, the cyclone desander skid 1, self-cleaning filter skid 2, seawater heat exchanger skid 3, and ultrafiltration system skid 4 of the seawater pretreatment system are all integrated skid-mounted structures. All parts of each skid are installed in a common frame. Each process unit has modular functions, compact structure, small footprint, high space utilization, easy installation, simple pipelines and convenient operation and management. It should be noted that the platform space is limited and the equipment is arranged in large quantities. The skid structure realizes modular functionality, equipment intensiveness, and simple operation. It should be noted that the platform equipment is highly concentrated, the on-site pipeline construction space is small, and the skid structure greatly reduces the pipeline connection of the entire system.

Claims

1. A skid-mounted integrated seawater pretreatment system for oil platforms, characterized in that: include: Cyclone desander, self-cleaning filter, seawater heat exchanger, ultrafiltration system; cyclone desander, self-cleaning filter, seawater heat exchanger, ultrafiltration system adopts a skid-mounted structure to form four skid-mounted units, among which the cyclone desander skid-mounted unit, self-cleaning filter skid-mounted unit, seawater heat exchanger skid-mounted unit, ultrafiltration system skid-mounted unit are sequentially connected to form an integrated structure, which is used for seawater to flow through the four skid-mounted units in sequence for treatment.

2. The skid-mounted structure integrated seawater pretreatment system for oil platforms according to claim 1 is characterized in that: The skid-mounted unit of the cyclone desander integrates the water pump, cyclone, pipelines and valves, instruments, electric control box and frame. The water pump, cyclone, pipelines and valves, instruments and electric control box are all installed in a common frame.

3. The skid-mounted structure integrated seawater pretreatment system for oil platforms according to claim 1 is characterized in that: The self-cleaning filter skid-mounted unit integrates the motor, pipelines and valves, filter screen, electric control box and frame. The motor, pipelines and valves, filter screen and electric control box are all installed in a common frame.

4. The skid-mounted structure integrated seawater pretreatment system for oil platforms according to claim 1 is characterized in that: The seawater heat exchanger skid-mounted unit integrates the heat exchanger, pipelines and valves, instruments and frames. The heat exchanger, pipelines and valves, and instruments are all installed in a common frame.

5. The skid-mounted structure integrated seawater pretreatment system for oil platforms according to claim 1 is characterized in that: The ultrafiltration system skid-mounted unit integrates water pumps, ultrafiltration membranes, ultrafiltration membrane tanks, pipelines and valves, instruments, electric control boxes and frames. The water pumps, ultrafiltration membranes, ultrafiltration membrane tanks, pipelines and valves, instruments, and electric control boxes are all installed in a common frame.

6. The skid-mounted structure integrated seawater pretreatment system for oil platforms according to claim 1 is characterized in that: The ultrafiltration system skid-mounted unit adopts an immersed ultrafiltration system, using membrane separation technology to replace traditional sedimentation tanks and conventional sand filtration units.

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